A sprinkler head is installed on a ceiling surface or a wall surface in a building and provided with a nozzle that can be coupled to a pipe connected to a water source at one end and a thermo-sensitive actuator at the other end. In a normal condition, the thermo-sensitive actuator supports a valve body that closes the nozzle.
As a conventional sprinkler head, a sprinkler head of FIG. 13 is known (PTL 1). The sprinkler head 50 has a structure in which a pipe connection portion 51 and a frame 52 are screwed together by a screw 51A. When the pipe connection portion 51 and the frame 52 are screwed together, a lever 55 engaged with an inward flange 52A located at the lower end of the frame 52 and a saddle S are displaced toward the pipe connection portion 51 and a valve body 54 pressed by the displaced saddle S is closely attached to a nozzle end 53, so that the nozzle end 53 is blocked.
A slit-shaped opening 52B is formed over the inward flange 52A with which the lever 55 engage. The opening 52B is formed, so that a beam-like portion 52C is formed in the frame 52 under the opening 52B, and the inward flange 52A including a step portion is formed on an inner circumference of the beam-like portion 52C. The lever 55 is engaged with the inward flange 52A, so that, when a load is added to the beam-like portion 52C in a position opposite to the opening 52B (downward direction in FIG. 12), a deflection occurs and resilience is obtained. In other words, when the pipe connection portion 51 and the frame 52 are screwed together, a deflection occurs in the beam-like portion 52C by the lever 55 disposed under the opening 52B, and the deflection causes a spring force. The spring force has a function to explosively eject components of a thermo-sensitive breakup portion 57 to the outside of the sprinkler head 50 when the sprinkler head is actuated, so the spring force is useful for preventing a lodgment (clog of components of the thermo-sensitive breakup portion 57 when a breakup occurs).